HOUSTON — It's every parent's worst nightmare when they send their child off to school, they'll come home injured.

Laura Welch tells NewsFix a teacher at Bush Elementary school abused her 7-year-old son who struggles with autism. The mother said he attends school under the Structure program, which teaches students to express themselves constructively.

"He does struggle with some appropriate reaction to normal situations," Welch said.

The boy was brought into a "cool-down room" during an emotion outburst, and that's where the mom said a teacher let him have it.

"My son was slapped across the face," Welch said.

She claims he was also hit in the shoulder and chest area. Welch shared pictures of the bruises with NewsFix, saying the injuries were from the attack.

The mother said she complained to Alief ISD about the injuries.

District officials responded to NewsFix in an email saying Alief ISD Police Department conducted two investigations, during which the accused teacher was placed on administration leave, after Welch sent them an email in late September.

In both, school administrators said investigators interviewed several teachers, students and Welch's son. The district said it also reviewed surveillance footage from the classroom.

"Both investigations determined that there was no evidence to support the allegations," the district said.

The district tells NewsFix, the police department refered the claim to Child Protective Services to investigate the child's home situation.

NewsFix reached out to CPS, which confirmed it did conducted an investigation into the child's injures. But an agency official said CPS could not release the outcome of its investigation.